1. Field of the Invention
The present invention relates to a person counting device, a person counting system, and a person counting method that counts the number of persons passing a counting area set in a monitoring area using an image obtained by imaging the monitoring area.
2. Description of the Related Art
In a store such as a convenience store, a monitoring camera system that monitors a person in the store using an image imaged by a camera installed in the store is widely spread. However, if the number of persons passing a counting area set in the store is counted using an image imaged by the camera, a degree of customer interest with respect to a display shelf of products of interest can be checked by setting the counting area on a path in front of the display shelf of the products of interest. In this way, an improved way of displaying the products can be considered, and thus, it is possible to improve the sales and profits of the store.
As a device related to the counting of the number of passing persons in the store, a technology is known in the related art, in which a detection line is set on the image of the camera which images the monitoring area, and the number of persons crossing the detection line is counted (refer to Japanese Patent Unexamined Publication No. 2005-148863). In a case of an image obtained by imaging the monitoring area by a camera having a predetermined angle of view, so-called a box camera from an oblique direction, there is a problem of an erroneous counting occurring. In contrast, in this technology, since the counting is performed considering the movement direction of the persons, the accuracy of counting the number of passing persons can be improved.
In addition, a technology is known, in which, when the monitoring area is divided into a walkable area (effective area) and a non-walkable area (non-effective area) and in a case where a traffic line acquired by tracking the person is crossing the non-walkable area, such an abnormal portion in the traffic line which passes through a non-walkable area is eliminated (refer to Japanese Patent No. 4408916). In this technology, a normal traffic line remains in the divided state by eliminating the abnormal portion of the traffic line, and an editing operation for restoring the complete traffic line is performed by an operator's visual operation with respect to only the normal traffic line. Thus, the highly accurate traffic line can be acquired.
In counting the number of persons passing through the counting area, the traffic line for each person is acquired and then, the traffic lines passing through the counting area can be counted. However, in a case where there is an abnormal traffic line, errors may occur in the number of persons passing through the counting area.
That is, in a case where the tracking of the person fails on the way due to the influence of so-called occlusion in which a person hiding behind the display shelf becomes invisible and thus an interruption of the traffic line occurs, if traffic line correction processing of connecting two traffic lines is performed, there is a case where the abnormal traffic line passing through the non-walkable area can be obtained. In addition, in a case where there is an erroneous detection of the person in the tracking of the person, that is, there is an error also in the position of the detected person, there is a case where the abnormal traffic line passing through the non-walkable area can be obtained. As described above, in a case where the traffic line passes through the non-walkable area, an omission in counting the traffic lines occurs in the counting area where the traffic line does not pass in the walkable area of the counting area where the person actually passed, and thus, the accuracy in the number of persons passing through the counting area deteriorates.
With respect to the problems described above, in the technology disclosed in prior art of the former, the number of persons passing through the detection line is counted and only the trajectory of the person (traffic line) around the detection line is acquired. However, in a case where the detection of the person fails due to the influence of the occlusion or the like or in a case where there is an error in the position of the detected person in the detection of the person, there is no change in the fact that the omission in counting the number of persons occurs. Therefore, in any way, it is not possible to solve the problem in that the accuracy of the number of persons passing through the counting area deteriorates.
In addition, the technology disclosed in prior art of the latter is nothing but a technology in which only the normal traffic line can be acquired by eliminating the abnormal portion from the traffic lines acquired by the tracking of the person. The technology is advantageous in the operation of restoring the complete traffic line, but, in any way, cannot solve the problem of the omission in counting the traffic lines due to the abnormality of the traffic line. Therefore, there has been a problem in that the accuracy in counting the number of passing persons cannot be improved.